feat(removeFalsy): add removeFalsy function and tests (#150)

Author: jsnelgro

src/index.js

@@ -19,6 +19,7 @@ import isNullOrWhitespace from './is-null-or-whitespace'
 import isToday from './is-today'
 import startsWith from './startsWith'
 import removeDuplicates from './remove-duplicates'
+import removeFalsy from './remove-falsy'
 import add from './add'
 import subtract from './subtract'
 import subtraction from './subtraction'
@@ -77,6 +78,7 @@ export {
   isToday,
   startsWith,
   removeDuplicates,
+  removeFalsy,
   add,
   subtract,
   divide,

src/remove-falsy.js

@@ -0,0 +1,12 @@
+export default removeFalsy
+
+/**
+ * Original source: https://stackoverflow.com/questions/32906887/remove-all-falsy-values-from-an-array
+ *
+ * This method removes any falsy values in an array while maintaining the array's order
+ * @param {Array} arr - the array filter
+ */
+ 
+function removeFalsy(arr) {
+  return arr.filter(Boolean)
+}

test/remove-falsy.test.js

@@ -0,0 +1,51 @@
+import test from 'ava'
+import {removeFalsy} from '../src'
+
+test('removes false from array', t => {
+  const n = [false]
+  const expected = []
+  const actual = removeFalsy(n)
+  t.deepEqual(actual, expected)
+})
+
+test('removes zero from array', t => {
+  const n = [0]
+  const expected = []
+  const actual = removeFalsy(n)
+  t.deepEqual(actual, expected)
+})
+
+test('removes empty string from array', t => {
+  const n = ['']
+  const expected = []
+  const actual = removeFalsy(n)
+  t.deepEqual(actual, expected)
+})
+
+test('removes null from array', t => {
+  const n = [null]
+  const expected = []
+  const actual = removeFalsy(n)
+  t.deepEqual(actual, expected)
+})
+
+test('removes undefined from array', t => {
+  const n = [undefined]
+  const expected = []
+  const actual = removeFalsy(n)
+  t.deepEqual(actual, expected)
+})
+
+test('removes NaN from array', t => {
+  const n = [NaN]
+  const expected = []
+  const actual = removeFalsy(n)
+  t.deepEqual(actual, expected)
+})
+
+test('maintains array order', t => {
+  const n = [NaN, 1, 2, false, undefined, 3, 0, '', 4, 5, null]
+  const expected = [1, 2, 3, 4, 5]
+  const actual = removeFalsy(n)
+  t.deepEqual(actual, expected)
+})